What constitutes negligence as a proximate cause in a medical malpractice case?

A defendant's negligence qualifies as a proximate cause where it is a substantial cause of the events which produced the injury (Derdiarian v. Felix Contr. Corp., 51 N.Y.2d 308, 315, 434 N.Y.S.2d 166, 414 N.E.2d 666 [1980] ). However, [w]here the acts of a third person intervene between the defendant's conduct and the plaintiff's injury, the causal

[57 N.E.3d 1091]

[37 N.Y.S.3d 54]